1. Field of the Invention
The invention relates to a device for encoding a stream of databits of a binary source signal into a stream of databits of a binary channel signal, wherein the bitstream of the source signal is divided into n-bit source words, which device comprises converting means adapted to convert said source words into corresponding m-bit channel words. The invention also relates to a device for decoding a stream of data bits of a binary channel signal obtained by means of the encoding device, so as to obtain a stream of databits of a binary source signal.
2. Description of the Related Art
An encoding device mentioned in the foregoing is known from the book `Coding techniques for digital recorders` by K. A. Schouhamer Immink, chapter 5.6.7, pp. 127 to 131, Prentice Hall (1991). The book discusses an encoder for generating a (d,k) sequence which satisfies the parameters: rate 2/3, (1,7), which encoder is also proposed by Cohn et al in U.S. Pat. No. 4,337,458. The known encoding scheme suffers from the presence of a DC level which may become excessively large and therefore introduces distortion in communication systems which can not handle a DC component, as well as distortion in any recording of data in magnetic media.